1. Field of the Invention
The present invention relates in general to sun roof devices for wheeled motor vehicles, and more particularly to sun roof devices of a type which generally comprises a pair of guide rails extending along respective sides of a roof opening, two pairs of front and rear sliding shoes slidably engaged with the guide rails, lifting arms carried by the rear sliding shoes, and a lid having a front portion carried by the front sliding shoes and a rear portion carried by the lifting arms. More specifically, the present invention is concerned with an improvement in construction of the rear sliding shoe.
2. Description of the Prior Art
In order to clarify the task of the present invention, one of conventional sun roof devices will be described, which is shown in Japanese Patent Second Provisional Publication 6-35252.
The sun roof device of the publication comprises a pair of guide rails which extend along respective sides of a rectangular opening formed in a roof, two pairs of front and rear sliding shoes which are slidably engaged with the guide rails respectively, lifting arms which are respectively carried by the rear sliding shoes and a rectangular lid which has a front portion carried by the front sliding shoes and a rear portion carried by the lifting arms.
In response to movement of the front and rear sliding shoes along the guide rails with an electric power, the lid is brought to four essential positions, which are a tilt-up position wherein the lid is placed in the roof opening with its rear end somewhat raised from a rear end of the roof opening, a full-close position wherein the lid is neatly received in the roof opening to fully close the same, a tilt-down position wherein the lid is placed in the roof opening with its rear end somewhat lowered from the rear end of the roof opening and a full-open position wherein the lid is drawn rearward and received in a lid containing space of the roof thereby to fully open the roof opening.
To permit the lid to take the above-mentioned positions, each rear sliding shoe and the corresponding lifting arm are constructed and arranged in the following manner.
The rear sliding shoe is of a single-block structure constructed of an aluminum die-cast and comprises mutually spaced first and second guide walls which have respectively first and second guide slots. The lifting arm has at opposed surfaces thereof first and second guided pins which are slidably engaged with the first and second guide slots of the rear sliding shoe. That is, due to movement of the first and second guided pins in the respective guide slots, the lid is moved to take the tilt-up, full-close and tilt-down positions.
In order to put the first and second guided pins into the first and second guide slots upon assembly of the shoe, one of the first and second guide walls is formed with a leading slot which is led to one of the first and second guide slots. After the first and second guided pins are brought into engagement with the first and second guide slots with an aid of the leading slot, the leading slot is covered with a cover plate. The cover plate is fixed to the corresponding guide wall by means of bolts.
However, due to inherent construction, the above-mentioned rear sliding shoe has the following drawbacks.
First, due to provision of the guide slots in the first and second guide walls, the mechanical strength of the sliding shoe is poor. One measure for solving this problem is to increase the thickness of each guide wall of the shoe. However, increase in thickness tends to induce a bulky, heavy and expensive construction of the sliding shoe and thus that of the entire of the sun roof device.
Second, due to provision of the guide slots in the guide walls, the guided pins are easily viewed from the outside of the shoe, which lowers the aesthetic value of the sun roof device.
Third, due to provision of the cover plate with which the leading slot is covered, there is inevitably produced a gap between the cover plate and a wall of the corresponding guide slot. The gap tends to cause generation of a noise when the corresponding guided pin abuts against the same during operation of the lifting arm.